Slat angle and spacing stabilization for face-printed, tilted-slat puzzle

ABSTRACT

A slat puzzle having segments of a target image printed on the faces of slats, adjacent to at least one edge of each slat. The target image elements are made visible by offsetting each slat against the next. The offset is achieved by tilting the slats in a box or rack. The slats are constrained by interaction between the slats and the assembly box or rack to fall into uniform tilt and spacing.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a continuation-in-part of U.S. patent application Ser. No. 12/767,116 filed Apr. 26, 2010, which claims priority on U.S. Provisional Patent Application No. 61/214,682, filed Apr. 27, 2009. This application also claims priority on U.S. Provisional Patent Application No. 61/460,259 filed Dec. 29, 2010 and U.S. Provisional Patent Application No. 61/462,491 filed Feb. 3, 2011, the entireties of all of which are hereby incorporated by reference into this application.

BACKGROUND OF THE INVENTION

Picture puzzle is a generic term for an article of manufacture that is used by people, primarily for amusement and recreation. In using a picture puzzle, a person typically assembles a coherent target image from disordered elements of the target image. Jigsaw puzzles are the most common type of picture puzzle and have been a staple amusement/recreation item for many years. Typically printed onto a finished side of a sheet of stiff cardboard, which is then die-cut, most jigsaw puzzles are of the interlocking type, where assembled pieces cannot be separated from one another without lifting one out of the plane of the puzzle. Variations have included puzzles of identically shaped interlocking pieces, puzzles printed on both sides, oddly shaped puzzles, puzzles of identically shaped rectangular pieces, and puzzles where the target image is a uniform color with no markings.

Picture puzzles have also been printed on sets of blocks of square cross section, including cubes, often with each side of each block being a section of one of four or six pictures. U.S. Pat. No. 1,636,371 to Kenney, U.S. Pat. No. 2,491,296 to Beder and U.S. Pat. No. 2,581,492 Lowe et al. are of this type. Puzzles on arrays of long, slender pieces, both square, as described in U.S. Pat. No. 2,581,492 to Lowe et al., and round, as described in U.S. Pat. No. 1,257,432 to Wetzel, are known.

Also known are picture puzzles exhibiting surface relief. Interlocking picture puzzles that include joining sections of the puzzle at angles to form three-dimensional shapes are also known.

In the late 1990's, OddzOn, a subsidiary of Hasbro, Inc., sold a product called Slivers (“a slice of puzzle fun!”). The Slivers product consisted of about 50 plastic pieces, each approximately a tenth of an inch thick, one inch wide, and four inches long. The slats were stacked face to face and the stack placed on its side in a closely fitted plastic box. Vertical slices of a target image were printed, or laminated, onto the exposed edges of the slats. When the slats were properly oriented and ordered in the stack, the target image would be assembled.

Additionally, the Slivers product had a different picture on each side of the stack, which enhanced the challenge of solving the puzzle by forcing the solver to discern which long edge of each slat belonged to each of the two pictures. And the two pictures were out of sequence with each other, so, when one was assembled, the other was disassembled. Each slat was formed with tabs projecting from opposite corners, which, in cooperation with the box, enforced the end to end orientation of the visible edge of a slat, while not enforcing which long edge was placed upward. This type of puzzle is generically referred to in this disclosure as a slat puzzle.

Particular advantages of a slat puzzle over a jigsaw puzzle, which provides a similar challenge to a solver, are: a more compact structure, particularly during assembly; the area for assembly being identical to the area of the finished puzzle; that the puzzle can easily be moved about or stored while partially assembled; and there is no need for a level surface for assembly.

SUMMARY OF THE INVENTION

The present invention addresses slat puzzles of the type that have target image elements printed on the faces of the slats, adjacent to their edges; those elements made visible by offsetting each slat against the next. More particularly, the present invention addresses such slat puzzles where the offset is achieved by tilting the slats in cooperation with a box or other structure.

In one embodiment, the assembly box supports the slats uniformly on the flat bottom of the box and generally confines the slats within the sides (left and right) and ends (top/upper, away from the viewer/user; and bottom/lower, toward the viewer/user) of the box. The dimensions of the slat stack, in relation to the length of the box (end to end), generally determine the tilt of each slat in a uniformly tilted slat stack. A wedge at the top end of the box more specifically determines the tilt of each slat in a uniformly tilted slat stack.

Edge-printed, slat puzzle can be assembled in a square-sided box roughly the same size as the printed face of the slat stack. If the box is slightly longer than the slat stack, the slats can be tilted to reveal part of their faces. With a small tilt angle, uniformity across the slat stack is a natural consequence. There are substantial advantages to more extreme tilting of the slats. As the slats are tilted, the exposed area of each slat becomes larger. Correlatively, with the exposed area held constant, greater tilt means thinner material, for savings in production cost and shipping. Visually, the thinner slats permitted by the increased tilt, and the increased angle (away from the viewer/user) itself, both help to insure that the slat edges will not become visible and intrude on the target image.

Where the slats have no edge printing, and particularly where the slats are tilted at smaller angles (e.g. 45 degrees) it is preferred to use relatively dark (particularly black) substrate (or color the slat top edges) so that, should the slat edges come into view, interference with the target image will be minimized. The following description addresses slats that are printed on their faces, adjacent to their edges, and includes slats that are also printed on their edges.

It is not always a trivial task to manually adjust the slat stack to be uniformly tilted (to produce uniform offsets). The present invention provides a slat rack and/or slat configuration that causes interaction between the slats and the assembly box structure to constrain the behavior of the slats, biasing them to fall into uniform tilt and spacing.

The invention will be more fully described by reference to the following drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic diagram of an assembled folded-slat puzzle with extended image slices.

FIG. 2A is a schematic diagram of a slat core with extended image slice.

FIG. 2B is a schematic diagram of a full single fold slat.

FIG. 2C is a schematic diagram of a partial single fold slat.

FIG. 2D is a schematic diagram of a full double fold slat.

FIG. 2E is a schematic diagram of a partial double fold slat.

FIG. 2F is a schematic diagram of a reverse double fold slat.

FIG. 2G is a schematic diagram of a slat core with label.

FIG. 2H is a schematic diagram of a slat core with larger label.

FIG. 2I is a schematic diagram of a fully wrapped slat core.

FIG. 2J is a schematic diagram of a slat core with two labels.

FIG. 2K is a schematic diagram of a multi-fold slat with web.

FIG. 3 is a schematic diagram showing image slices extended by three different (but neither exclusive nor exhaustive) methods.

FIG. 4 is a schematic diagram of a representative variation of an extended image slice.

FIG. 5A is a schematic diagram of a printed web substrate with lateral perforations, and with successive extended image slices printed in irregular sequence.

FIG. 5B is a schematic diagram of a printed web substrate with successively printed extended image slices oppositely oriented in an irregular order.

FIG. 6 is a schematic diagram of a slat puzzle with tilted slats.

FIG. 7A is a schematic diagram of slats with target image slices applied near the edges of the faces of the slats.

FIG. 7B is a schematic diagram of slats with target image slices applied near the edges of the faces of square slats.

FIG. 8 is a section through a slat stack in a square-sided, flat-bottomed box.

FIG. 9 is a section through a slat stack, supported by a wedge, in a square-sided box.

FIG. 10 is a section through a slat stack held between two wedges.

FIGS. 11A and 11B are sections through wedge and sawtooth slat racks, supporting typical, rectangular slats.

FIG. 12 is an elevation at one end of eared slats in a sawtooth edged, square-sided box.

FIG. 13 is an elevation at one end of eared slats in an ordinary, square-sided box.

FIG. 14 shows a die cutting pattern for eared slats.

FIG. 15A is an elevation/section at one end of single-edged slotted slats in an ordinary square-sided box.

FIG. 15 B is an isometric view of single-edged slotted slats in an ordinary square sided box.

FIG. 16 shows a face of a single-edged slotted slat with flared slots.

FIG. 17 shows a face of a reversible slotted slat.

FIG. 18 shows a face of a reversible hybrid (slots and ears) slat.

FIG. 19 shows a face of a single-edged slotted slat with shortened earlobes.

FIG. 20 shows a face of a single-edged slotted slat, organized for longitudinal stepping.

FIG. 21 shows a face of a reversible slotted slat, organized for longitudinal stepping.

FIG. 22 diagrams the relationship between a target picture and a set of longitudinally displaced slats,

FIG. 23 shows a slat pattern A generated from a slice of a target image, a modified form C of that pattern, and a second slat pattern B generated from an adjacent slice of the target image.

FIG. 24 shows a die cutting pattern for concentric square slats.

DETAILED DESCRIPTION

The drawings and description that follow illustrate varied embodiments of the invention taught herein. Wherever possible, the same reference numerals will be used throughout the drawings and the description to refer to the same or like parts.

FIG. 1 shows a completed slat puzzle 500 according to the teachings of the present invention. Puzzle 500 is comprised of a stack of a plurality of slats 400. Slats 400 are shown in sequence to complete target image 600 properly assembled. Extended target image slices 100 are formed by extending target image slices 650 perpendicular to their long axes.

Extended target image slices 100 appear on the edges 401 and extend to faces 402 of slats 400. Preferably, extended target image slices 100 appear on the slat edge with the original target image slice essentially parallel to the long axis of the slat. Preferably, slats 400 are fabricated by printing extended target image slices 100 onto substrates 200, scoring or crimping or creasing or scratching or otherwise forming lines into the substrates (to insure clean, precise folds), and folding and gluing. For example, substrate 200 can be cardboard.

FIG. 2 illustrates several embodiments of slats 400. In general, a slat is a dimensionally stable, three-dimensional, rectilinear, object.

Slat 400, as understood herein, has two relatively large, relatively flat, generally parallel faces 402, each having a length and breadth, and, separating those faces, a relatively narrow edge 401, having a thickness. Where the edge changes character or direction, such as, a right angle, sections of the edge can be referred to as separate edges, as in common speech. In addition, the common use of the term “slat” implies a substantially greater length than breadth. Those proportions are generally preferred for the present invention, but they should not be taken as limiting. A preferred slat has a rectilinear shape. It will be appreciated that other shapes of slats 400 can be used in accordance with the teachings of the present invention.

Dimensions for embodiments of the invention can vary widely, but it is generally preferred that slat thickness be from about five thousandths of an inch for example (roughly half the thickness of a mass market cardboard playing card) to about one-quarter of an inch; breadth from three-eighths of an inch to an inch and three-quarters; and length from two and one-half inches to eighteen inches. The dimensions for slats in a particular embodiment generally fall in the same end (or middle) of the range for each of the dimensions. Slats 400 in puzzle 500 are preferably, but not necessarily, the same size (including thickness).

Slats 400 comprise cores 300 and/or folded substrates 200. Substrate 200, as understood herein, is of the size necessary to form one slat 400. However, it should also be understood that, at any stage of production, several or many substrates 200 may be part of the same sheet or web of material. The sheet or web may be sheared, or otherwise divided, to separate the substrates 200, or perforated, in any pattern, preferably one leaving little attachment, for later, manual separation.

Material choices for cores 300 and substrates 200 will be readily apparent to one skilled in the art. The preferred material for cores 300 and substrates 200, without cores, is what is commonly called cardboard including, for example, chipboard, card stock, and corrugated, all of which are relatively inexpensive and ubiquitous. For slats 400 comprising folded substrates, the cardboard is preferably coated. For example the cardboard can be coated with clay or faced with higher quality paper laminated to the surface to be printed. For use in combination with cores 300, thinner substrates 200, preferably paper, are preferred.

Core 300 can be almost coincident in size and mechanical characteristics with slat 400 that's built with it. Without the images, the slats of previously known slat puzzles are cores 300 under the present parlance. FIG. 2A shows such a slat core 300, onto which an extended target image slice 100 is applied. Extended target image slice 100 can be applied by any conventional or unconventional technique, such as, for example, pad printing, hand painting, or silk screen.

FIG. 2B shows slat 400 without a core 300. Substrate 200, the length of a desired slat 400 and twice its breadth, is printed with extended target image slice 100, then scored along its long centerline to insure a clean fold, preferably by a die associated with the printing equipment; then folded; and, preferably, glued.

Alternatively, the printing can be onto a pre-scored substrate 200. It should be noted that gluing is not always necessary, and unglued slats 400 of this and other forms are preferred in some embodiments, as a slight tendency to unfold can provide a gentle spring action to space slats 400 evenly in a box, while allowing the slat stack to be compressed for slat manipulation. Slats 400 can be proportioned so that the spring action doesn't cause the slat stack to buckle. Also, unglued slats 400 can present some manipulation difficulties, such as tending to catch on one another as they are inserted into the stack.

Slat 400 of FIG. 2C is folded only near one edge of substrate 200, while the opposite edge remains unfolded. This form is unlike most preferred slats 400, in that the thinner, unfolded edge is not fully supported and stabilized by adjacent slats in the stack, but it can be especially useful, for example, in an arrangement where slats 400 are inserted into individual slots in an assembly rack. Separators in the rack would then not force the printed edges apart.

FIG. 2D shows substrate 200 with two folds, to form slat 400 that is uniform in thickness and can carry an extended image slice on each of two edges.

Slat 400 of FIG. 2E is similar to that of 2D, having two folds in which there is a break in material between the folds to provide a slight savings in material.

FIG. 2F shows reverse double fold slat 400. A two sided puzzle 500 comprising such slats, requires substrates 200 to be printed on both sides.

In FIGS. 2G, 2H, 2I, and 2J, thin substrates 200, carrying extended target image slices 100, are bonded to cores 300 in various configurations. Bonding can be by any conventional or unconventional technique, such as glue, staples, or tape, including using adhesive labels as pre-bonded substrate material.

Shown in FIG. 2K, large slats 400 can be formed as narrow hollow boxes, with no cores. Dimensional stability is insured by end closures and/or an internal diagonal web that can be a continuation of the box material. In this case, the slat edge is formed by two right-angle folds instead of a single fold. An edge defined by two folds can also be useful in any of the previously described slat configurations, where it is desired to have a particularly flat edge and/or with relatively thick substrate materials.

FIG. 3 shows three kinds of extended target image slices 100. In each case, artwork for target image 600, acquired in any conventional or unconventional way as, for example, by photography, drawing, clip-art, or gyotaku (Japanese fish printing), is adjusted or cropped to an appropriate size for a puzzle 500. The artwork is usually the same size as the intended slat stack, but the following techniques may require original artwork slightly larger than that. A target image is understood to be essentially the same size as the slat stack with which it is associated. Target image 600 is then divided into a plurality of target image slices 650 to match the number of slats 400 intended for puzzle 500. As a result, target image slices 650 are approximately as wide as intended slats 400 are thick.

Each target image slice 650 is then extended perpendicular to its long axis to any desired degree to present solving information and/or for other design reasons to form extended target image slice 100. Extended target image slice 100 is extended preferably to at least three times the thickness of slat 400.

In FIG. 3A, target image slice 650 is extended by copying and concatenating adjacent target image slices 650 of target image 600. Thus (with the slices numbered in their original, assembled sequence, from top to bottom) slice 3 could be extended by copying slices 1 and 2 and concatenating them to its top edge and copying slices 4 and 5 and concatenating them to its bottom edge.

The resulting image is preferably continuous, not divided into strips. With extension by copying, the original art work is preferably longer, in a direction perpendicular to the slices, by the width of one extended target image slice, at least. That is to provide material for extension of the extreme slices 650 of target image 600.

The described image manipulation can be done, almost manually, by making several physical copies of the artwork and slicing them apart on a paper cutter. The several copies are needed because successive extended slices overlap each other. Common methods of computer image manipulation, including those in commercial software packages like Adobe PhotoShop, particularly slice and divide tools, are suitable, and usually preferred.

In FIG. 3B, target image slice 650 is extended by stretching either each slice 650 or the entire target image 600 before slicing. Conventional computer software, including Adobe PhotoShop, provides handles and tools to stretch images and tools to slice them. Alternatively, a stretching operation can be accomplished by physically dragging an original image along the glass of a copy machine or scanner as it is copied, but that's not necessarily a practical approach. A stretched version of target image 600 can also be relatively easily created as original artwork.

In FIG. 3C, the slice is extended by repetition. A starting pattern, can be entire target image slice 650 or a representation of target image slice 650. Such a representation can be, for example, a slender sample parallel to the long axis of target image slice 650, or an essentially linear image, maybe no more than a pixel wide, showing the average color and average brightness at closely spaced cross sections of target image slice 650. The starting pattern is then repeated several or many times, each repetition being displaced by its own width, generally perpendicular to the long axis of the slice, to form extended target image slice 100.

Repetition of the image slice itself can, in principle, be accomplished with a paper cutter and glue if one has enough copies of the original art work and a great deal of time and patience. Alternatively, a computer, with conventional commercial software, such as Adobe Photoshop, can be used for repetition of target image slice 650 less tediously and more precisely. A slender sample of the slice is likewise relatively easily selected and repeated, using the same software. To repeat an essentially linear representation is similarly straightforward.

In an embodiment of extension by repetition, preferred particularly for relatively thick slats 400, slender samples are selected at the extreme edges of target image slice 650. Target image slice 650 is left whole, as a portion of extended target image slice 100 that will eventually be registered on edge 401 of slat 400, as in a mass market cardboard slat puzzle. The balance of extended target image slice 100 is generated by repetition of the extreme edge samples. As a result, edge 401 of slat 400 will bear a detailed portion of target image 600; faces 402 of the slats will bear linear indications of the edge information.

In a similar preferred embodiment of extension by repetition, an essentially linear representation of target image slice 650 is repeated at each edge of target image slice 650 to form extended image slice 100.

With extension by repetition, regardless of which starting pattern is used, registration with the slat edge may not be critical. Essentially, any portion of such extended target image slice 100 that falls on the edge of the slat will present the same sequence of color and brightness along the slat edge as any other portion. Only where slats 400 are relatively thick and entire target image slices 650 are retained in expanded target image slices 100 will imprecise registration of expanded image slices 100 on edges 401 of slats 400 be noticeable.

An essentially linear representation of the cross sections of the image slice has to be generated, before it can be repeated. Commercial image processing software can be used. One method is to shrink an image slice perpendicular to its long axis, and to use the shrunken slice as the starting pattern for repetition.

With repetition of an essentially linear representation of target image slice 650, image detail will be removed, which can result in a more challenging puzzle 500, especially where slats 400 are relatively thick. However, completed target image 600 will show as a coarser grained version of the original artwork. Where slats 400 are relatively thin, the difference will not be so noticeable. In either case, extended image slice 100 need not be precisely registered on slat edge 401.

Each kind of extended image slice has characteristics that can provide advantages or disadvantages in particular embodiments. Those image slices extended by copying must be precisely registered on the slat edges; they provide a lot of information for the solver; they are very simple to generate. By comparison, those image slices extended by stretching are not so sensitive to registration on the slat edges; provide somewhat less information to the solver; are a little more difficult to generate; cause the assembled target image to be discontinuous from slat to slat. Those image slices extended by repetition may not need to be precisely registered on the slat edges; in many cases provide minimal information for the solver; are sometimes more difficult to generate; allow more varied design choices. Also, the visual texture of assembled puzzles will depend on the kind of extension.

Varied design choices include non-uniform extension (different image components to different extents) of an image strip, such as differential extension by color or by area, or by any other characteristic, or even randomly. For a preferred embodiment of this effect, a roughly linear starting pattern is repeated, essentially as described above. But, as the repetitions are laid down, successive repetitions are modified by fading out different colors at different rates. Or some color can be abruptly terminated after so many repetitions, an additional color after so many more repetitions, and so forth. This effect is illustrated in FIG. 4. In FIG. 4, repetition of an essentially linear representation of a target image slice 650 has resulted in a pattern of color bands. Also, successive repetitions can be slightly displaced parallel to the long axis of the slice, several stepping in one direction and then several stepping back, to present the slice extension in a wavy pattern. For an effect similar to repetition of a very narrow target image slice 650, or of a linear representation of a target image slice 650, extension can be accomplished by physically smearing the ink of each image slice after (or during) printing.

Neither the discussion of kinds of target image slice extension nor the design choice descriptions should be taken as exhaustive.

Extended target image slices 100 have to be organized for printing, which should be understood to mean any reasonable method of reproduction. Whether each substrate 200 is to be printed individually, or as part of a sheet or web, the order and orientation of the successively printed extended target image slices 100 have to be determined. If the intent is to produce an assembled puzzle 500, substrates 200 are best printed with extended image slices 100 in sequence. However, it is preferred to present puzzle 500 unassembled, so its extended target image slices 100 should be printed in irregular, for example, not readily apparent order. Some puzzles 500 will also benefit by presenting the extended target image slices 100 oppositely oriented in irregular order. That is especially important in such embodiments as those with slats 400 of FIG. 2D, where it is desirable to disguise the orientation of the slats by disconnecting the correct orientation of the information from the orientation of the butt seam on one face of the slat 400. Also, for slats 400 shown in FIG. 2D, or others, used in a two-sided puzzle 500, extended target image slices 100 of a first target image 600 and extended target image slices 100 of a second target image 600 must be arranged so that each slat 400 will comprise, on opposite edges, extended target image slices 100 from each of the target images 600.

FIG. 5 diagrams printed web substrates 200 prior to cutting and folding. In FIG. 5A, successive extended target image slices 100 are printed out of their original sequence. In FIG. 5B, successive extended target image slices 100 are printed in an irregular sequence of orientation. FIG. 5A also shows the web as laterally perforated between successive substrates 200.

Contrary to the diagram representation, one should not expect to find the slat sequence numbers on slats 400 of a real puzzle.

Target image 600 can be any graphic image, simple or complex, realistic or not, in colors or not. However, to be useful, target image 600, or at least a substantial portion of it, must be distinguishable as properly sequenced or not. Target images 600 should recognize the unique physical structure of a slat puzzle. For example, a picture that includes a recognizable major element that crosses many slats 400 at an angle, may severely reduce a puzzle's difficulty. It should be noted that an adjustment of the angle of the slices can be helpful to make such artwork more useful; the artwork need not be square to the slat orientation.

While it is generally preferred that each slat 400 be the same length, the lengths of the slats can be divided, into equal segments or not, and identically to other slats or not and assembled into the same assembly box or adjacent boxes, or into one box divided into columns or other sections.

As shown in FIG. 6, an assembly box can be arranged, with or without a sloped side or internal wedge, to allow the slats to tilt, thereby offsetting each slat from the next to expose the faces of the slats, adjacent to the edges of the slats. With the slats tilted sufficiently away from an observer, the slat edges are hidden from view; there is no apparent distinction between a slat with printing on its edge and one without. The slats shown in FIG. 6 are numbered 400/800 as either type can be used in such an embodiment.

Where the slats are so tilted in relation to one another, they can be printed only on their faces, adjacent to edges. That does not require folding of a substrate 200. FIG. 7A shows a slat 800 comprising target image slice 650 on slat face 802. FIG. 7B shows a slat 800 with four edges of equal length and extended target image slices 100 printed on portions of face 802 adjacent to each edge. Expanded target image slices 100 are shown to terminate short of the corners of slat 800 so they do not overlap at the corners. This is a design choice; expanded target image slices 100 might instead be allowed to overlap at the corners, or be mitered at the corners.

A similar square slat 400 can comprise a substrate 200 with expanded image slices 100, wherein each of the four edges is folded to present the expanded image slices 100 on edges 401 and faces 402 of slat 400. In such an embodiment it is preferred to miter the corners of the folds, even where expanded image slices 400 do not reach the corners. Alternatively, the substrate can be cut to reduce the length of the sections to be folded over, so they do not interfere.

Likewise, expanded image slices 100 can be printed onto substrates 200 that are then folded over the edges of cores 300 to form square slats 400.

And, of course, other polygonal shapes can be used in the same manner.

Additionally, if the material of core 300 is sufficiently porous, inks or dyes printed onto its face can be absorbed into slat core 300 and will be visible, without folding, at slat edge 401 as well as slat face 402 of slat 400.

FIG. 8 illustrates an embodiment of slat puzzle 500 including slats 800 manufactured identically to ordinary playing cards, which (after centuries of product improvement) are particularly comfortable to manipulate and, for a paper product, extremely durable. Slats 800 are printed with slices of a target image (or target images), rather than (or in addition to) the mass market cardboard playing card faces (and/or backs). The target image slices are preferably, not necessarily, extended, as described above. It is known that playing cards are relatively heavy and slippery, so they readily distribute themselves according to gravity and other forces. If one rests a deck of cards on its edge on a flat surface, the opposite/top edge of the deck will remain flat, the cards distributed uniformly, as the cards are tilted substantially from the vertical orientation. A double deck (104 cards), set on a long edge and tilted, for example, 63½ degrees from vertical, can make an excellent face-printed, tilted-slat puzzle.

As the tilt for slats 800 becomes more extreme, gravity no longer tends to enforce the uniform tilt and spacing of slats 800. It becomes easier for slat 800 to lift and displace its neighbor. FIG. 9 illustrates an embodiment having slats 800 supported at end 801 of the stack by wedge 25. For example, wedge 25 can have a 26½ degree angle supporting the stack of slats 800 at a 63½ degrees. For slats 800 in a straight- sided assembly box 50, slats 800 may readily slide under one another, making it difficult to manually equalize the spacing of the card/slats. In this particular instance, control can be substantially facilitated by confining slats 800 between two opposing surfaces. FIG. 10 illustrates an embodiment having a second, inverted, wedge 25, secured at end 802 of stack of slats 800 which can be used to constrain the stack with slats 800 filling the space between wedges 25, thereby uniformity is automatically achieved in stack of slats 800.

Individual slats 800 can only be removed and repositioned by sliding them parallel to themselves. The size of wedge 25 can be reduced such that it bears against only part (preferably including the bottom edge) of the front face of slat 800, rather than covering most of the surface to allow easier removal and repositioning of slats 800. Inverted wedge 25, of any extent, can be mounted to, or made of, resilient material, to allow manual displacement during manipulation of slats 800. Following is discussion of a face-printed, tilted-slat puzzle, to be manufactured substantially similar to a mass market cardboard jigsaw puzzle.

For this puzzle, 75 slices of 8×9½ inch, vertically/portrait oriented, target image are preferably, not necessarily, extended. Extending the image slices can provide increased printing and die-cutting tolerances, gives the user/assembler a better look, and make the slats more attractive.

For this example, image slices for a single target image are formatted for printing onto 8×⅞ inch slats, on a 27×22 inch sheet (typical of mass market cardboard jigsaw puzzles) to accommodate, with room to spare, three, 8 inch wide columns, each with twenty-five, ⅞ inch wide slats.

Similar to mass market cardboard jigsaw puzzles, this example is preferably manufactured from 1/16 inch thick chipboard with a laminated, printed surface. The slats are separated by die-cutting, similarly to mass market cardboard jigsaw puzzles, in this case producing rectangular pieces.

As described above, a 9½ inch high target image for this puzzle is divided into 75 slices for processing and printed to 75, 1/16 inch thick slats. The total thickness of the 75 slats is 4¾ inches. Tilting the slats 45 degrees would offset each slat by its 1/16 inch thickness, which would support a target image no more than 4¾ inches high. But, the target image for this puzzle is intended to be 9½ inches high, and the slices are each ⅛ inch. In order to produce an offset of ⅛ inch per slat, the slats must be tilted to (90−arctan 0.5=) 63 1/2 degrees from vertical.

With a design angle of 63½ degrees, and 75 relatively narrow slats, manual adjustment for uniform tilt is bothersome. Retaining these relatively stiff slats at end 801 and end 802 of a stack of slats 800 (with wedge and inverted wedge) can be effective to enforce uniformity, but, as noted above, limits the degree of freedom with which the slats can be manipulated. With only wedge 25 at end 802, the top of slat stack of slats 800 control the tilt angle when in a smooth box, slats 800 tend to slide about in the box, pushing each other out of alignment. If box 25 is provided with increased friction (as by adding a soft rubber pad inside the bottom of the box) slats 800 resist being moved to their correct positions.

It is possible to take advantage of easy slat movement by assuring that the slats are biased to move to uniform position and orientation, as they come to rest. FIGS. 11A and 11B illustrate sawtooth slat rack 35, having preferably one tooth 804 per slat 800 (although two or several teeth per slat will sometimes be effective), appropriately angled to reflect the tilt for the desired offset. Slat rack 35 can be used with stack of slats 800 urging, automatically produce uniform tilt and spacing in stack of slats 800, particularly with little manual where/when top slat 800 is supported by an appropriate wedge 25. In this embodiment, wedge 25 is integrated into slat rack 35 at end 801 without constraining opposite end 802 of the stack. However, when slats 800 are removed (singly and in groups) for repositioning, slats below the break can tilt back into the break.

The term “sawtooth” is meant to include toothed, crenelated, crenate, crenulated, and other, regularly ordered support elements, having an integral number of repetitions per slat distance; that distance being determined by the actual slat thickness and the desired tilt angle. Regular order does not require that the tooth form be constant (or change regularly), but that is preferred. Regular order is not obviated by occasional anomalous teeth (regularly spaced or not), as might receive slats for a puzzle designed with occasional anomalous (e.g. particularly wide) slats, defining a skeleton into which narrower slats are interposed.

Slat rack 35 incorporating a slat support wedge 25 and teeth 804 can have low manufacturing costs. A washboard type sheet, slat rack 35, shown in FIG. 11B, (edges turned downward, so as not to present a hazard to fingers manipulating the slats) can be vacuum formed from thin, rigid, plastic sheet, such as commonly used for take-out food boxes and lids, and dropped into assembly box 50. A pair of sawtooth rails can be used slat rack 35, shown in FIG. 11A, each preferably incorporating wedge 25, that can be die cut along with slats 800, from the same typical jigsaw puzzle blank (where the 75 slat pattern had room to spare). The pair of rails can be made to engage for support with holes in the sides of the box, or additional slat rack members can be die cut from the same puzzle blank. Die cutting the slat rack along with its puzzle, permits customized slat racks, e.g. with occasional anomalous teeth. An inexpensive slat rack is formed from a sheet of single faced corrugated cardboard with corrugations facing up in the bottom of assembly box 50.

A change in position of the sawtooth rails produces an even more stable configuration.

FIG. 12 shows slats 850 are provided with ears 851. Ears 851 are short projections at the upper corners of the slats (that's at both ends of the target image slices). Ears 851 are formed by removing, at each end of each slat, a narrow strip, for example ⅛ inch by preferably ⅔ of the slat width (i.e. the greater dimension visible at either end of the slat), as shown in FIG. 14. FIG. 14 shows a pattern for die-cutting that produces slats with ears 851 being ⅓ of the slat width, and waste only at the outside edges of the die. It will be appreciated that smaller ears (i.e. less than ⅓ the slat width) can be more stable, and are often preferred. Also, it is generally preferred to arrange printing layouts with slats arranged to avoid adjacent active slat edges, thereby greatly reducing the die cutting precision required. It is also generally preferred that, in such cases, rows of slats be separated, so as not to leave uncontrolled dropouts (i.e. so that the waste bits are connected to each other).

With eared slats 850, a durable slat rack can still be preferably die-cut from the puzzle blank. In an alternate embodiment as shown in FIG. 12, the puzzle box can act as a slat rack for further reducing manufacturing costs. Eared slats 850 of this example are 7¾ inches long, and have a pair of ⅛ inch ears, for a total length of 8 inches. Eared slats 850 are placed crosswise in box 60 that is slightly over 7¾ inches wide. Eared slats 850 hang by ears 851 on top edges 852 of the sides of box 60. Top edges 852 of the sides of box 60 are cut into a sawtooth to fit the thickness of eared slats 850, at the tilt angle that will produce the desired offset. This arrangement can ensure uniform slat spacing, but (unless eared slats 850 are delicately balanced about ears 851) is not sufficient to urge eared slats 850 to uniformly align to that angle. Eared slats 850 of this example are ⅞ inch wide and 1/16 inch thick. If the depth of box 60 is calculated, or empirically determined, for the bottom edge of each hanging eared slat 850 to contact the bottom of box 60 when eared slat 850 is hanging at the desired angle, eared slat 850 will therefore come to rest at that angle. In this example, the required depth of box 60 from the root (lowest point) of the sawtooth, is ¼ of an inch. In practice, it isn't necessary for the box depth to be so limited; it's only necessary to support the bottom edges of the slats at a couple of points with parts of a slat rack structure, preferably die cut from the puzzle sheet.

With hanging eared slats 850, the angle of each slat is individually controlled, so, when slats are removed for repositioning, there is no change in the tilt of slats above or below (upstream or downstream of) the gap. As shown in FIG. 13, with this element of stability, the eared slat configuration can be adequate in an assembly box 50, without the additional spacing control afforded by the sawtooth. Each eared slat 850 is biased, by support of ears 851 and the bottom of assembly box 50, to hang at the predetermined angle. Therefore, in an assembly box 50 (or rack) that contains its design complement of slats, the slats will also fall into equal spacing.

Slats with ears that are simply rectangular projections at the ends of the upper edge of each slat can be inadvertently skewed, causing the slats to fall from the rails (or box edges) from which they hang. This can be a mild annoyance to the puzzle assembler and may limit the ways in which the puzzle can be handled, stored, and/or displayed.

This limitation can be overcome by extending the ears substantially beyond the slat rack, but that strategy does not resolve another limitation introduced by ears that are simply rectangular projections at the ends of the upper edge of each slat. The ears define the upper edges (those with the ears) and lower edges of the slats. Puzzle picture slices appear only at (and/or on) the upper edges. Accordingly, where rectangular slats allow complex challenges with picture elements on both long edges of each slat, slats with ears appear to be more limited.

Ears can be supplemented or reconfigured so that the slats are better retained on the support rails, while re-enabling two-edge puzzles.

It should be understood that face-printed, tilted slat puzzles with rectangular slats can have slices of eight different pictures; four of the pictures on the four edges of one face of the slats and the other four on the four edges of the opposite face of the slats. For the relatively slender slats of this example (i.e. those with two long edges and two insignificant edges) the number of pictures is reduced to four. For relatively slender slats with only a single active face (which are substantially more economical to produce) the number of pictures is reduced to two. A two-edge puzzle (with disparate slat sequences) can be a significantly greater challenge than a single-edge puzzle, particularly where the colors and patterns of the two pictures are similar.

FIGS. 15A, 15B and 16 show slats 875 that are similar to eared slats 850. Rather than removing the lower corners of the ends of the slats, each slat 875 is provided with a pair of slots 852 extending from its bottom edge about two-thirds of the way to its top edge. Slat 875 is thereby able to hang on a pair of support rails 859, similar to eared slat 850. With slots 852 engaging rails 859 of assembly box 50, or rails within or without the assembly box, slats 875 are secure from slipping off the rails.

FIGS. 17 and 18 show reversible slats. FIG. 17 has a pattern of slots 852 at top edge 856 and bottom edge 857 of slat 875 that are 180 degrees rotationally symmetrical about the center of slat 875. FIG. 18 is similar, but material between the extreme slots and the ends of slat 875 has been removed to form ears 876. In each embodiment, top edge 856 and bottom edge 857 are indistinguishable. If support rails for slats 875 in this assembly are positioned in assembly box 50, one rail will be farther than the other from the centerline of assembly box 50.

FIG. 19 shows a variation, with slat portions 854 extending beyond slots 852 to form ear lobes 855. Ear lobes 855 are shortened to reduce possible mechanical stress on the narrowest portion of slat 875.

FIGS. 20 and 21 show slats 875 with a plurality of slots 852. FIG. 20 shows a single-edged slat, preferred for embodiments with longitudinal adjustment; FIG. 21 shows a reversible slat variation. On a pair of support rails, these slats 875 can be shifted longitudinally. Puzzle 500 built on a stack of such slats 850 can be far more challenging than one in which the slat stack has uniform edges (i.e. with no protruding slats).

Target images for mass market cardboard slat puzzles and tilted slat puzzles with longitudinal adjustment are preferably wider than the length of a slat by the distance of maximum longitudinal adjustment. FIG. 22 shows the relationship between a target image 600 and an assembled set of longitudinally displaced slats 875. Each slat 875 carries a, preferably extended, image slice that appears along the full length of the slat.

A preferred completed slat stack will have half the slats, on average, shifted to the left and half shifted to the right (preferably in no particular order).

While the slats of FIGS. 20 and 21 are to be adjusted incrementally, useful puzzles with infinite adjustment are possible. A mass market cardboard slat puzzle (i.e. with zero tilt angle; no offset) with infinite longitudinal adjustment can be nothing more than a stack of slats held together by rubber bands. Incremental adjustment in a mass market cardboard slat puzzle (or in some embodiments of tilted slat puzzles) can be controlled with very shallow slots engaging even a single rail.

As stated above, the manufacture of the puzzle of this example is virtually identical to that of mass market cardboard jigsaw puzzles. That includes usual choices of substrate materials, printing, and die-cutting methods. Jigsaw puzzle manufacture is mature and economical, readily available technology. For this example, ears and/or slots are preferably formed by the die that divides the sheet (or web) into slats.

In other embodiments, it might be preferred to form the ears and/or slots after the slats are separated (or if they were made separately). A simple die arrangement, such as used to punch binder holes and slots in printed materials, can be used to punch individual slats or groups of slats. An entire set of slats can be clamped into a rectangular block and the block sawn or routed in a direction perpendicular to the slats.

Any other suitable cutting method, including, but not limited to, lasers, water jets, and the like, can be used to form the slats, ears, and/or slots.

Support rails for eared and/or slotted slats can be the edges of the assembly box or inserted within the assembly box. A pair of cardboard strips, each on edge and straddled by slat slots, are sufficient to control the slats in cooperation with the surface on which the strips and slats rest. A preferred rail arrangement for economical cardboard puzzles is a simple rectangle folded from a strip of chipboard, placed on edge on the bottom of the assembly box, and secured inside the ends of the box, adjacent to the top and bottom of the slat stack. For a little more stability the rails can be the edges of a narrower box, inside the assembly box.

It is often preferred to flare/widen the open end of slots 852, to allow more casual placement of the slats onto the support rails, as shown in slat 875 of FIG. 16.

In most embodiments, it is preferred that the rails on which the slats are supported be somewhat thinner than the slots to broaden manufacturing tolerances and to help insure free movement of the slats.

The preferred proportions and size for this example particularly support the use of slat patterns that are extensions by repetition, as shown in FIG. 3C, of each slat's associated image slice. However, it is here preferred to introduce an additional effect to make each slat pattern somewhat harder to comprehend as part of the target image; thereby increasing the puzzle challenge. These patterns are also incidentally attractive.

FIG. 23 shows slat patterns 100, generated by repetition from a slice of a target image 600. However, in these patterns, every second repetition is inverted top to bottom (perpendicular to its long axis). The top strip of the slat pattern 100A is a copy of the fourth slice of the target image 600; the second strip of that pattern is the same slice, inverted top to bottom; the third strip is upright; the fourth inverted.

In practice, it is advisable to add an additional strip at the top; that is so, if the top edge of a slat is cut imprecisely, the pattern will nevertheless continue to the edge of the slat. For the same reason, if the slat pattern is to continue to the bottom edge of the slat, an additional strip should also be added at the bottom of slat pattern 100.

If the slats are carefully manufactured, so that the top edge of each slat falls precisely at the top edge of an upright strip, the assembled target image will be precisely rendered. If the slats are die cut above or below that line, the assembled target image will appear textured (increasingly so, with greater deviation from the line).

The manufacturing scenario for this example (i.e. essentially identical to mass market cardboard jigsaw puzzle manufacturing) uses a single die to cut all the puzzle pieces from a single sheet of cardboard, to which is mounted a printed paper sheet. Mass market cardboard printing tolerances (which, e.g., accommodate fine registration of colors over large areas) easily assure quite precise placement of slat patterns on the printed paper sheet. Modern die manufacturing ordinarily produces quite precise knife placement. Registration of the die with the printing is more difficult to control, particularly as production speeds are increased.

Slat patterns described herein are capable of producing a continuous, non- textured, assembled target image; and it exhibits a vibrant, attractive, visual effect.

Imprecise registration of these patterns produces texture in the assembled target image that may not be desirable. However, precision in the printing and in the die insure that each slat pattern will be positioned virtually identically on each slat. Where precision cutting is impractical, that consistency supports various approaches to controlling the degree and character of the texture (i.e. discontinuities in the resulting assembled image) of a target image on an assembled slat puzzle.

One approach, shown by the relationship between slat patterns 100A and 100B of FIG. 23, is to use an almost identical slat pattern 100 structure on each slat, but to modify the slat pattern 100 for every second slat, by beginning with an inverted band. Slat pattern 100B, generated from the fifth slice of target image 600, has an upright second band, rather than top band. The two slat patterns, 100A and 100B, therefore follow the modified sequence. It should be noted that, while this approach limits the overall degree of discontinuity, it also imposes a minimum level of discontinuity.

Another approach, to reduce the effect of an imprecise die strike, is to compress the inverted bands and expand the upright bands. Slat pattern 100C of

FIG. 23 is so derived from slat pattern 100A.

Production and shipping costs can be reduced (or play value increased) for some configurations of face-printed, tilted-slat puzzles (particularly those with die cut slats). Slats with broad faces are preferred for some embodiments; particularly useful are square slats, printed with slices of four different images (for example, four views of a single 3D scene). Also contemplated are two sided slats with slices of eight different images, or with the same four images on each side, but with one side color coded at its corners to distinguish the elements of each of the four pictures.

Whatever the artwork, square (or otherwise broad) slats, while relatively easy to manipulate, use up a lot of coated/laminated, printed cardboard. For conventional (or unconventional) edge-printed slat puzzles that would be a substantial limitation. For face-printed, tilted-slat puzzles it's an opportunity. The center of a square slat is not necessary to the operation of the puzzle. For example, 6 inch square slats could have 2 inch square holes punched at their centers without appreciably affecting manipulation of the puzzle.

For the cost of artwork preparation and another slight increase in die cost, the extraneous 2 inch squares can be additional puzzles. With the same tilt angle, aspect ratio of the large and small target images is maintained by reducing the number of slats for the small puzzle. In this example, one third of the 2 inch square slats produced from a 6 inch square puzzle will produce proportions similar to the six inch puzzle. Thus, for each 6 inch puzzle with, for example, 75 slats, three 2 inch puzzles with 25 slats each will be manufactured at almost no cost, to be included as a bonus, or packaged and sold separately.

For the cost of artwork preparation and a slight increase in die cost, two four inch, 37 piece puzzles can be added. One four inch piece will be left over. In some printing environments, production can be organized to produce another four inch bonus puzzle with the production of every thirty-seven, six inch puzzles. Alternatively, a number of slats like 60, 72, 84, 96, or 120 can be used.

FIG. 24 shows a die cut pattern for slat 810 within slat 805, which is within slat 800.

The above-described examples use a 63½ degree tilt, producing an offset that is double the slat thickness. Various degree tilt can be used. The 63½ degree tilt was chosen to produce a useful/pleasing aspect ratio in a puzzle based on a double deck of playing cards, and to stay within the production parameters of a single typical mass market cardboard jigsaw puzzle. For some other embodiments, tilt angle for an offset triple the slat thickness is about (90−arctan 1/3 =) 71½ degrees, and tilt angle to produce a quadruple thickness offset is about (90−arctan ¼=) 76 degrees.

It is to be understood that the above described embodiments are illustrative of only a few of the many possible specific embodiments that can represent applications of the principles of the invention. Numerous and varied other arrangements can be readily devised in accordance with these principles by those skilled in the art, without departing from the spirit and scope of the invention. 

1. A slat puzzle comprising a plurality of slats, each slat comprising on at least part of a face adjacent to an edge thereof an image slice of a target image, wherein the slats are offset to reveal the image slices.
 2. The slat puzzle of claim 1 further comprising: a holder for holding the slats, wherein elements of the target image elements are made visible by offsetting each of the slats against an adjacent slat, the offset being achieved by tilting each of the slats in the holder and wherein the slats are constrained by interaction between the slats and the holder, to tend to fall into essentially uniform tilt and spacing.
 3. The slat puzzle of claim 2 wherein the holder comprises at least two parallel rails and at least one track; and wherein each of the slats is suspended on the rails and bears against the track, thereby determining the angle of repose of the slat.
 4. The slat puzzle of claim 3 wherein the holder is an uncovered box, the top edges of two sides of the box being the rails, and the bottom of the box being the track.
 5. The slat puzzle of claim 3 wherein each of the slats comprises at least two projections at opposite ends of an upper part of each of the slats; the projections resting upon the rails.
 6. The slat puzzle of claim 5 wherein the projections are integral with the slat.
 7. The slat puzzle of claim 5 wherein at least one of the projections extends beyond and at least partially over the rail, thereby defining a slot that is generally perpendicular to the upper edge of the slat.
 8. The slat puzzle of claim 7 wherein the projections are integral with the slat.
 9. The slat puzzle of claim 7 comprising at least one slot extending from each of two edges of the slat.
 10. The slat puzzle of claim 9 comprising at least three slots extending from one edge of the slat.
 11. A slat puzzle wherein each of the slats comprises at least two slots; the slots engaging with at least one rail, to enable each slat to be retained in at least two alternate longitudinal positions.
 12. The puzzle of claim 1, wherein the image slices are extended generally perpendicular to the edges, along the faces of the slats.
 13. A method of making a slat type picture puzzle, comprising the steps of: a) preparing artwork for a target image; b) dividing the target image into a plurality of slices; c) extending each of said slices, generally perpendicular to its long axis; and d) applying each of the extended slices to an edge and onto at least one face of a slat.
 14. The method of claim 13, wherein each of the extended slices is applied to the slat by: printing the extended slice onto a substrate; and folding the substrate to form the slat.
 15. The method of claim 13, wherein the succession of printed, extended image slices is irregular.
 16. The method of claim 15, wherein successively printed, extended image slices are oppositely oriented in an irregular order.
 17. The method of claim 15, wherein successively printed, extended image slices are irregularly out of sequence.
 18. The method of claim 17, wherein substrate material is perforated between adjacent substrates.
 19. A picture puzzle comprising: a plurality of slats, each of the slats bearing on at least part of an edge a slice of a target image; wherein a typical slat comprises a substrate that is folded roughly parallel to the long axis of the extended image slice to form the edge of the slat bearing the slice.
 20. The puzzle of claim 19, wherein a typical slat comprises a substrate that is folded roughly parallel to the long axis of the extended image slice; and wherein at least two folds form an edge of the slat. 